Impact screw driver



J. C. M CORKHILL IMPACT SCREWDRIYER Sept. 7, 1948.

Filed Aug. 9, 1944 Patented Sept. 7, 1948 UNITED STATES PATENT OFFICEinursoriscnswinmvhn Jesse MeCorkhill, Xenia, ()hio ApplicationAligust 9,1944,:seria1 No. 548,729 r I I This invention relates toa tool and moreparticularly to a tool adapted to-transla-te linear impacts into rotaryor torque impacts.

In certain industries and'trades it'is necessary to remove screws, nuts,bolts,'rivets and other fastening devices that have becomei'set inposition. For example,-in-, airplanestscrews are used in assemblingmetallic parts. In the event the parts become damaged, or for some otherreason must be removed, difficulty has been experienced in looseningthescrews, for the reasonthat the screws may have -rusted or-corrodedaso asto be impossible of removal by the use of-a manually operated screwdriver or other-tool used in unscrewing the screws.

An object of this invention is to provides, tool wherein the tool may bestruck or hit by ahammer or other impact providing-device 'ina directionparallel to the longitudinal axis of theltool and the longitudinal axisof the screw, which tool translates the linear impact movementlinto arotary or torque ,impelling movement, so as :to utilize the linearmovement i-n forcing an adapter or implement into engagement with, thework to be actuatedand utilizing the rotaryfor torque impelling movementto rotate the work. v

Another object of this invention is to provide ahammer driventool foractuating fastening devices, illustrative 30f which are sscrcw threadedmembers wherein a linear impact movement is used in forcing theimplement..intowengagement with the fastening device and a rotaryorwtomue movement is used in actuating the fasteningr'device, such asESCIBW threaded parts, which :tool is easily produced, easilyhandledl'eiificientsand dependable and at the .same time inexpensive.

Other objects and iadvantageszreside 'inithe construction of parts,thexcombinationthereof and the mode of operation, which wil1 become moreapparent from the following description.

Referring to the drawings, Figure 1 discloses a side elevational view ofthe tool. Figure 2 is a longitudinal sectional view taken substantiallyon the line 2-2 of Figure 1.

Figure 3 is an end view adapterremoved. a my Figure 4 discloses alongitudinal cross sectional view'of a modification. 1 In the drawings,the reter enc'e character I0 indicates a tubular mainbodyportion-onhandle sleeve member of the implement. It is provided witha knurled hand-grip portion surrounding the periphery of the handle. Thelower end taof the tool with the lclaim; (01." 1 45-53) threadedaperture "if is located near the end of the handle and extends radially.

Theiinternal threads or splines lflc engage a spirally grooved implementsupporting member or spirally splined spindle I2, having a reducedportion {4 projecting outwardly fromthe handle I-D, which reducedportion is preferably square in cross sectional area and is providedwith a recessreceiving a ball l6, spring urged outwardly bya smallhelical spring l8 and adapted to engage and look a work engagingimplement .20, shown in dotted lines.\ This. work engaging implementmaybe a screw driver, a socket wrench or any other type of implementadaptedto engage the work. H l v The upper end of the tool supportingmember I2 is reduced. at l2a and projects into the enlarged recess orcavity Hid. Asuitable retaining ringor spring 22 is seated in a,grooveof the reduced portion l2a and engages a Washer 24, seated againstthe shoulder we. ,,'I'he washer! is mounted for movement with theimplement supporting member I 2 A compression spring 26 is mountedbetween the washer 24 and a capping member 28, provided with a reducedportion 28a projecting into the recess 10d and locked in position by asuitable .setscrewtfl, engaging the threads of the aperture III). Thecapping memberZS constitutes the impact receiving portion-of the tool. 3

A suitable oil retaining member 32ism'ounted in the tapering portionIlla of the handle Inland surrounds the implement supporting member [2,so {as to. oil the, implement supporting member. The implementsupporting member l2, and the parts carried thereby, are always biasedoutwardly by the compression spring 26, which in- .cidentally, in movingthe implement supporting member outwardly into the position shown inFigure-2, rotates theimplement supporting memher, 2, together with theadapter carried thereby.

The direction of the threads, on the implement supporting member I2 isselected'either, to loosen a screw or to tighten a screw. The pitch ofthe grooves, ispl-ines or threads is so selected that a reciprocatory orlinear impact applied to i an impact'receivinghead of the tool in adirection par- ..allel to the longitudinal axis of the spindle:translates the linear impact movement into a rotary i a screw having akerf is to be removed an adapt er simulating a screw driver is. selectedand mounted on the end of the implement support j recess.

agonal, a socket adapter may be selected. Like- 40 'wise, if nuts are tobe removed, sockets engaging the nuts are selected.

hammer the head 28 applying the blows parallel 5 to the longitudinalaxis of the tool, so as to cause the adapter to move towards the work.Instead of a manual hammer being used, any other suit- I able hammeringdevice or tool may be used, such as a pneumatic hammer or anelectromagnetic hammer. Due to the spiral arrangement of the groove inthe spindle [2 the linear impact 'applied to the implement is translatedinto a rotary, or

torque impact, tending to rotate the work. This .jars loose the screw,if it is to be loosened, or

whatever the work may be. If it is to be tightened, the impact may beused in tightening the parts. After each hammer blow, in the absence ofexternal forces, the head and hammer impact receiving member is restoredto the position shown in Figure 2. It may be that the operator may biasthe handle towards the work, thereby causing the adapter to firmlyengage the work in readiness for the linear impact that is beingtranslated into rotary impact.

This tool has been found very effective in rej moving screws from wingsof airplanes thathave been damaged and is used to remove screws-thatcannot be removed manually with the aid of conventional screw drivers.The adapter isselected for the particular work. In the event it is ascrew to be loosened and the head of the screw is provided with a kerf,a straight edge screw driver is used. In the event the screw is providedwith 1 cross, grooves, an adapter fitting into the cross. 5

grooves is selected. In the event the head of the screw is provided witha square, or a hexagon recess, an adapter is selected that will fit sucha If the head of the screw is square or hex- In the modificationdisclosed in Figured, the

tubular sleeve handle member 69 is provided with an internally threadedbore 62 receiving a thread-- ed spindle 64 adapted to support a workengaging adapter. Thespindle is urged into the position shown in Figure4 by a compression spring 65 seated against a washer 68held in fixedrelation with respect to the end of the spindle by a Screw '10. Thespring 66 and the washer B8 are mounted in an enlarged recess 12.

The outer end of the recess is threaded and receives a threaded head orcapping member 14, held in position by a suitable set screw '16 seatedin a threaded aperture in the handle member 60. The lower end of thehandle is provided with a reduced cylindrical portion '18, provided witha longitudinally extending key seat 80, receiving a suitable detent 82in a sleeve or ferrule 84 of member 86 held upon the 8' end of thespindle 64 by a screw 88, extending into a circumferential groove 90 inthe spindle 64. A collar portion 92, either integral with, pressfittedupon or'fixedly secured to the spindle 64,

engages member 86, so as to cause member"86:65 to move longitudinallywith respect to the handie 60. Member 86 is prevented from rotating withthe spindle by virtue of the detent 82'being seated in the key seat 80,so that member 86 may reciprocate on the handle 60 without rotating withthe spindle. Member 86 is mounted for nonrotary movement with respect tothe handle and is mounted for non-axial movement with respect to thespindle. 1

rotary movement. I "sleeve provided with spiral grooves, v a; rubber in-Number In the device disclosed in the drawings, the parts have beenshown as metallic parts cooperating to translate reciprocatory movementinto Instead of using a metallic sert could be mounted between thespiral spindle 1 and the tubular sleeve, the rubber insert being rvulcanized to the metallic sleeve and thereby provide" a' 'resilient oryieldable impact translating vice-hasbeen described, it will beunderstood that within the purview of this invention various changes maybe made in the form, details, proportion and arrangement of parts, thecombination thereof and mode of operation, which generallystated'consist in a device cap-able of carrying out the; objects setforth, as disclosed and defined in the appended claim.

Having thus described my invention, I claim:

In a device for actuating a screw member or other turnable fasteningmeans, the combination including a tubular member having an internalbore provided with spiral grooves, said bore terminating in an enlargedportion terminating in a threaded portion, a spindle member providedwith spiral portions seated in the spiral grooves of the tubular member,means fixedly attached to the spindle member and including a washerseated in the enlarged portion of the cylindrical bore, ahammer-engaging capping member threadedly engaging the threads of thetubular member, a compression spring positioned between the 'cappingmember and the washer for urging the spindlemember into extendedposition, the spindle member projecting beyond the tubular'member, theportion of the'spindle member projectin beyond the tubular member beingprovided with an annular groove, a ferrule terminating in a tubularflange rotatably mounted on the spindle member near the end of thespindle member, the

flange telescopically engaging the tubular member, means for preventingrotation of the ferrule relative to said tubular member, means extendingfrom the ferrule into the annular groove for preventing longitudinalmovement'of the spindle 'member with respect to the ferrule withoutrota- -tion thereof, and a collar fixedly attached to the JESSE c.MCCORKHILL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date 701,941 Rowlands June 10, 1902 1,022,311Fegley Apr. 2, 1912 1,424,456 Fegley et a1 Aug. 1, 1922 1,731,979Krummel Oct. 15, 1929 1,937,645 Fegley et a1 Dec. 5, 1933 2,010,616;Walsh Aug. 6, 1935 FOREIGN PATENTS I Number Country Date 455,056 L"Germany, Jan. 24, 1928

